WO2003069021A1

WO2003069021A1 - Induction heating coil

Info

Publication number: WO2003069021A1
Application number: PCT/JP2002/001130
Authority: WO
Inventors: Mitsuhiro Maruyama; Keizo Fujimori; Haruo Sasaki; Osamu Okaniwa
Original assignee: Hitachi Zosen Corporation
Priority date: 2002-02-12
Filing date: 2002-02-12
Publication date: 2003-08-21
Also published as: JPWO2003069021A1

Abstract

An induction heating coil (21) provided with a gas injection opening communicating with the outside and a plurality of gas supply openings at specified positions of a gas channel (23) formed internally, wherein at least one gas supply opening is provided, in the inner circumferential surface thereof, with screw grooves (51, 52). The gas supply openings are opened in the side of a coil face constituting a planar induction electric field. A specific threaded member (55) is screwed into the screw grooves (51, 52).

Description

Description Induction heating coil Technical field

The present invention relates to, for example, an induction heating coil used as a heating means of a substrate processing (CVD: Chemical Vapor Deposition) apparatus for producing a crystal film or other thin films using a gas phase reaction. The present invention relates to an induction heating coil having a built-in gas flow path. Background art

As an induction heating coil used as a heating means of a base plate processing apparatus, for example, Japanese Patent Application Laid-Open No. H8-239295 discloses a method in which a gas flow path is provided inside the coil. Also disclosed are those in which a plurality of gas outlets are provided on the side facing the object to be heated (substrate), so that the source gas can be supplied directly to the substrate surface from the plurality of holes. Have been. It is disclosed that the gas blowing direction is set to be substantially perpendicular to the radial direction of the substrate, or to be blown at an inclined angle in the outer peripheral direction of the substrate. When trying to form a uniform crystal film or other thin film on the substrate surface, the source gas can be supplied uniformly onto the substrate, and the reacted source gas can be quickly discharged from the substrate. Desirably, the substrate processing apparatus is excellent in its uniformity.

However, according to the conventional substrate processing apparatus described above, the gas outlet is simply opened, so that the gas to be supplied is spread without control. In addition, since the gas outlet is always open, if the size of the substrate is changed from a large one to a small one in the same substrate processing equipment, the source that has been directly supplied to the substrate surface until then is The source gas is supplied directly to the susceptor on which the substrate is mounted, and a crystal film or other thin film grows on the susceptor, which is an unnecessary place, in the same manner as on the substrate surface. The problem is that the raw material gas is wasted, or if the grown crystals and the like are peeled off by some effect and adhere to the surface of the substrate where the reaction process is performed by multiplying the gas flow, the quality of the substrate deteriorates. Occurs.

In some cases, such as when the material of the substrate or the type of source gas has changed, it may be necessary to change the direction or size of the gas outlet, but an induction heating coil must be prepared in advance for each case. And are not economical.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a coil for induction heating which can cope with the specification of a substrate to be processed without changing the specification of a main part of the coil even if the size of the substrate changes. It is to provide Disclosure of the invention

An induction heating coil according to the present invention is an induction heating coil in which a gas inlet and a plurality of gas outlets communicating with the outside are provided at predetermined positions of a gas flow path formed inside, respectively. It is characterized in that at least one gas outlet has a thread groove on the inner peripheral surface.

The thread grooves need not be provided at all gas outlets, for example, only at the outer peripheral edge of the coil, at the outer peripheral edge and at the inner peripheral edge. It may be provided only for some items. The gas outlet may be perpendicular to the coil surface constituting the planar induction electric field, or may be inclined in a predetermined direction. The male thread member may be screwed into the thread groove, and may not be screwed. The screw member inserted into the thread groove may completely close the gas outlet, and has a through hole in the screw member screwing direction, and the through hole serves as a gas outlet. May be used. As the through-hole, a cylindrical hole whose axis coincides with the axial direction of the external thread member, a cylindrical hole whose axis is inclined with the axial direction of the external thread member, Various materials such as a spiral shape having the same axis direction as the screw member or an inclined axis can be used.

According to the induction heating coil of the present invention, when the size of the substrate is changed from a large one to a small one, the air outlet at the outer periphery of the coil is closed by a male screw member. By stopping the supply of the source gas to unnecessary portions, waste of the source gas and deterioration of the quality of the substrate due to crystals grown in unnecessary locations can be prevented. The male screw member may be provided with a through-hole for gas blowing in the screwing direction. This allows the hole direction, thickness, and shape to be changed due to changes in the substrate and raw gas. It can be easily handled and fine-tuned.

1 The gas outlet may be open on the opposite side of the coil surface that constitutes the planar induction electric field, facing the substrate to be heated, and on the opposite side. Sometimes. In the former case, the raw material gas or Cooling gas is supplied to the substrate, and in the latter case, a filling gas filling the space above the coil is supplied from the gas outlet.

Further, the coil is formed in a flat drop-wound shape, and in the center of the spiral, it is preferable that the gas outlet is provided on the side surface of the central part and has an inclination. The inclination includes not only the inclination toward the substrate facing surface but also the inclination with respect to the tangent direction of the central cylindrical surface in the horizontal plane. In this way, the supply of the raw material gas in the center, where the gas supply is likely to be insufficient or uneven, is improved, and the uniformity is improved.

In addition, as described above, a predetermined screw member may be screwed into the screw groove, and the screw member may be provided with a through hole for gas blowing that passes through the screw member in the screwing direction. is there. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a vertical sectional view showing an outline of a main part of a substrate processing apparatus as an example in which an induction heating coil according to the present invention is used.

FIG. 2 (a) is a plan view showing the top surface of the induction heating coil, and FIG. 2 (b) is a cross-sectional view taken along the line bb of (a). FIG. 3 is a bottom view showing the lower surface of the induction heating coil. FIG. 4 is an enlarged cross-sectional view of a gas outlet provided in the induction heating coil. (A) is a vertical cross-sectional view of a conductor element facing the central space, and (b) is a central space. FIG. 4 is a vertical cross-sectional view (radial direction) of a conductor element facing other than a portion, and (c) is a cross-sectional view (circumferential direction) along the CC line of (b).

FIG. 5 shows one embodiment of a cooling mechanism of a substrate processing apparatus. It is sectional drawing.

FIG. 6 is a block diagram showing a control unit of the substrate processing apparatus shown in FIG.

FIG. 7 is an enlarged cross-sectional view showing a screw groove provided in a gas outlet, which is a main part of the induction heating coil according to the present invention.

FIG. 8 is an enlarged sectional view showing an example of a male screw member screwed into the screw groove shown in FIG.

FIG. 9 is an enlarged sectional view showing another example of the male screw member screwed into the screw groove shown in FIG.

FIG. 10 is an enlarged sectional view showing still another example of the male screw member screwed into the screw groove shown in FIG.

Fig. 11 (a) is an enlarged cross-sectional view (a vertical cross-sectional view of the conductor element facing the central space) showing another example of the gas outlet provided in the induction heating coil. (b) is an enlarged cross-sectional view (horizontal cross-sectional view of the conductor element facing the central space) showing still another example of the gas outlet provided in the induction heating coil. BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a main part of a substrate processing apparatus as an example in which the induction heating coil according to the present invention is used. The substrate processing apparatus is housed in a water-cooled container (not shown), and has a reactor (1) having a cylindrical outer heat insulating wall (2), a cylindrical inner heat insulating wall (3), and a substrate loading / unloading door (4). ), And the first module installed on the top of the outer insulation wall (2). Heating means (5), substrate support means (6) located on top of the inner heat insulating wall (3), gas supply means (7) for supplying raw material gas and cooling gas to the substrate (S) surface, and inner heat insulating Second heating means (8) provided below the substrate support means (6) in the wall (3), and drive means (9) for supporting the substrate support means (6) and moving it in a required direction And a transfer port bot (10) for loading the substrate (S) into the reactor (1) and unloading the processed substrate (S.), and a cooling gas below the substrate support means (6). The apparatus is provided with a gas supply means (11) blowing out from the substrate, and a substrate lifting means (12) for lifting the substrate (S) from the substrate support means.

This substrate processing apparatus generates a crystal film or other thin film using a gas phase reaction, and a portion that causes a gas phase reaction is called a reaction section (la). At the lower part, which is another place, a loading / unloading section (lb) for transferring the substrate (S) outside the reactor (1) is provided.

Cooling water passages (2a) and (3a) are provided in the outer heat insulating wall (2) and the inner heat insulating wall (3), respectively.

The first heating means (5) has an induction heating coil (also referred to as a high-frequency coil) (21) according to the present invention. As shown in detail in FIGS. 2 and 3, the induction heating coil (21) is made of a conductor having a flat spiral shape, and has a gas flow path (23) opened upward, and a cooling passage. The coil body (22) in which the water flow path (24) is formed in a spiral shape, and the lid (25) that covers the coil body (22) from above and closes the openings of the flow paths (23) and (24) Become. In FIG. 2A, the lid (25) is omitted, and only the coil body (22) is shown. In the figure, (26) is an insulating gap, and this gap (26) is a special portion such as an end portion where the radial width of each conductor portion forming a spiral shape is an end portion. It is set to be constant except for.

As shown in Fig. 3, on the side of the coil body (22) facing the substrate (S) on the coil surface (opposed surface), as shown in Fig. 3, a plurality of gas outlets (29) (30) ) Is provided. As shown in detail in FIG. 4 (a), the gas outlets (29) provided at the periphery of the center space of the coil body (22) are inclined not toward the center but toward the center. It is formed as follows. The inclination angles (Kl) and (k2) of these gas outlets (29) are changed according to the positions where they are provided. As shown in detail in Figs. 4 (b) and 4 (C), the gas outlet (30) provided on the opposing surface other than the periphery of the central space of the coil body (22) is not located directly below. It is formed so as to be inclined toward the circumferential direction. As a result, the gas blowing direction on the surface facing the induction heating coil (21) is directed toward the center on the inner periphery of the coil (21) as shown by the arrow in FIG. It is designed to be blown out in the swirl direction.

The gas flow path (23) and the gas outlets (29) (30) of the induction heating coil (21) are used for blowing out the raw material gas during the gas phase reaction treatment, and It is also used for blowing out cooling gas after gas phase reaction processing. That is, the gas flow path (23) and the gas outlets (29) (30), the external pipe connected to the gas flow path, the plurality of gas pipes connected to the pipe, and the gas pipes The combination of the gas supply source for each of the source gas and the cooling gas, the gas supply pressure regulators, and the gas switching means enables a part to be built into the induction heating coil (21). The supplied gas supply means (7) uses the raw material on the substrate (S) surface. It is configured to also serve as a source gas supply unit for supplying a gas and an upper gas supply unit for blowing a cooling gas from above the substrate support means.

The substrate support means (6) is a circular plate-shaped susceptor (31) having a circular recess on the upper surface on which the substrate (S) is placed, and substantially horizontally at equal intervals from the upper end of the column (33). And a susceptor support arm (32) extending in three directions. One projection (32a) for supporting the susceptor (31) at three points is provided at the tip of the upper surface of each support arm (32).

The second heating means (8) is a heat reflecting plate (35) having a metal surface made of gold, silver, aluminum or the like and having a mirror surface. The heat reflection plate (35) is formed in a disk shape having a through hole in the center. As shown in FIG. 1, a cooling gas passage (36) for blowing a cooling gas vertically upward is provided above the heat reflecting plate (35). ) Is the lower gas supply means (11). Further, a cooling water flow path (37) for cooling the heat reflecting plate (35) is provided below the heat reflecting plate (35).

Although not shown, as the second heating means, the same induction heating coil as the first heating means arranged so as not to interfere with the pin receiver (43) may be used.

The driving means (9) includes a support (33) which is inserted into a central through hole of the heat reflecting plate (35) and whose upper end is integrated with the center of the susceptor support arm (32); Drives a motor (38) consisting of a stepping motor or servomotor that rotates 33) around a vertical axis, a lifting device (39) that moves the column (33) up and down, and a lifting device (39) And a control unit for performing the operation. The transfer robot (10) is a single-wafer type, and moves the board (S) between the horizontal direction to enter and exit the inner heat insulation wall (3) and the susceptor (31). It is necessary to move up and down to change.

The substrate lifting means (12) is provided with stepped through holes (41) provided at a total of three places on the substrate mounting surface equidistant from the center of the susceptor (31) and spaced 120 ° in the circumferential direction. ), A pin with a head (42) housed in the through hole (41) so as to be able to move up and down so that the top does not exceed the substrate mounting surface, and a susceptor provided below the susceptor (31). A pin receiver (43) provided at a 120 ° interval and concentric with the arrangement of the pins (42) of the receptacle (31) is provided.

As described above, the susceptor (31) is rotated by the motor (38) during the gas phase reaction process, but at the end of the process, as shown in FIG. It is stopped so that the pin receiver (43) is located just below, as in 42).

FIG. 5 and FIG. 6 show one embodiment of a cooling mechanism used in the substrate processing apparatus.

In the cooling mechanism shown in the figure, the three pin receivers (43) can be moved up and down by an elevating device (not shown), and the susceptor (31) has a plurality of ventilation holes (46). Are provided in a penetrating manner. Then, when the processing is completed and the rotation of the susceptor (31) is stopped so that the pin receiver (43) is located immediately below the pin (42), the three pins are kept in this state. The catch (43) is moved upward. As shown in FIG. 5, the pin receiver (43) passes through the through hole provided in the heat reflection plate (35), reaches the reaction section (la), and contacts the lower end of the pin (42). And this pin (42) becomes the pin receiver (43). Thus, the substrate (S) is lifted from the susceptor (31) by being moved upward. At this stage, the cooling gas is blown from the upper and lower gas supply means (7, 11) to cool the substrate (S) and the susceptor (31). Since the ventilation hole (46) is provided in the susceptor (31), the substrate (S) is also cooled by the cooling gas passing through the ventilation hole (46) of the susceptor (31). Susceptor (for example, made of carbon) (31) has a large heat capacity and is not easily cooled, but the substrate (S) is not in contact with the susceptor (31), so the effect of the susceptor (31) Cools without receiving.

The ventilation holes (46) of the susceptor (31) may be provided randomly, for example, as shown in FIG. 5 (b), or may be provided radially as shown in FIG. 5 (c). Good.

In this embodiment, all the pin receivers (43) are raised. However, the number of pin receivers (43) to be raised may be one, and in this case, only one pin (42) is provided. The lifted substrate (S) comes into contact with the susceptor (31) at one point on the outer peripheral surface. In this way, the substrate (S) and the susceptor (31) are not in point contact, that is, substantially not in contact with each other, and the substrate (S) is not affected by the susceptor (31). Cools without receiving.

Further, instead of moving only the pin receiver (43) upward, a relative movement may be performed in which the susceptor (31) is also lowered.

The susceptor (31) and the pin receiver (43) are moved vertically to the lower loading / unloading section (lb) while maintaining the positional relationship shown in Fig. 5. During this time, the spraying of the cooling gas is continued. Then, the cooled substrate (S) is carried out from the carry-in / out part (lb) by the carrying robot (10). As shown in FIG. 6, the control unit (40) of the substrate processing apparatus of this embodiment is provided with a gas supply pressure adjustment unit (44) and a vertical movement amount adjustment unit (45). The gas supply pressure adjusting section (44) separately adjusts the gas supply pressure of the upper gas supply means (7) and the gas supply pressure of the lower gas supply means (11). The gas outlet (29) (30) provided in the induction heating coil (21) through a valve provided in the pipe connected to the gas flow path (23) in (21). In addition to adjusting the downward pressure of the cooling gas to be blown out, the valve is provided through a valve provided in a pipe connected to the gas passage (36) of the heat reflecting plate (35), and the like. The upward pressure of the cooling gas blown from the gas outlet of the hot plate (35) is adjusted. The vertical movement amount adjusting section (44) separately adjusts the vertical movement amounts of the susceptor (31), the pin receiver (43), and the heat reflecting plate (35) via the elevating device (39).

According to the control unit (40), after the reaction treatment, first, the pin receiver (43) is moved upward, and the cooling operation is started in the state of FIG. Then, the susceptor (31) is moved downward while continuing the cooling work. At this time, the susceptor (31), the pin receiver (43) and the heat reflecting plate (35) maintain the positional relationship shown in FIG. 5, that is, the susceptor (31), the pin receiver (43) and the heat reflecting plate. (35) is simultaneously lowered at the same speed and moved to the loading / unloading section (lb). When moving the susceptor (31) from the reaction section (la) to the carry-in / out section (lb), supply the upper gas according to the descending amount of the susceptor (31) and the descending amount of the heat reflecting plate (35). Control is performed to increase the supply pressure of the means (7) above the supply pressure of the lower gas supply means (11). Therefore, the susceptor (31) As the heat reflection plate (35) descends, the distance from the induction heating coil (21) to the substrate (S) becomes longer, and the cooling gas near the substrate (S) is reduced. The balance between the upward pressure and the downward pressure is maintained by the control unit (40). Accordingly, it is possible to prevent contamination of the substrate (S) caused by the exhaust gas that has been blown down to the substrate (S) and moved downward and hits the substrate (S) again.

According to the induction heating coil of the present invention, as shown in FIG. 7, screw grooves (51) and (52) are formed on the opening side of the gas outlets (29) and (30) shown in FIG. Have been. The hole provided with the thread groove (51) shown in (a) of Fig. 7 is inclined toward the center axis direction of the coil, and the thread groove (52) shown in (b) of Fig. 7 is provided. The holes provided with are inclined in the direction perpendicular to the radial direction of the coil surface. Male thread members (54) (55) (56) are removably screwed into these thread grooves (51) (52) as necessary. The male screw members (54), (55) and (56) are those that completely block the gas outlet (54) and have through holes (55a) and (56a) in the screwing direction. (55a) The one in which (56a) is used as a gas blowing hole is appropriately used.

FIGS. 8 (a) and 8 (b) show that the screw grooves (51) and (52) shown in FIG. 7 are completely closed by the screw member (54). As the male screw member (54), a commercially available one can be used. For example, when the size of the substrate (S) is changed from a large one to a small one, the outer peripheral part of the coil (21) can be used. Used to close the gas outlet thread grooves (51) (52) at As a result, the supply of the source gas to the unnecessary portion is stopped, and it is possible to prevent waste of the source gas and deterioration of the quality of the substrate (S) due to grown crystals. FIGS. 9A and 9B show a male screw member (55) having a through hole (55a) in the screwing direction. According to the male screw member (55), the through hole (55a) is used as a gas blowing hole. The center of the through hole (55a) is aligned with the center of the male screw member (55). Therefore, gas can be blown out toward the center of the screw grooves (51) and (52).

FIGS. 10 (a) and 10 (b) show another example of a male screw member (56) having a through hole (56a) in the screwing direction. In the thread member (56), the center of the through hole (56a) does not coincide with the center of the male screw member (56), and is inclined in a predetermined direction. According to the screw member (56), the direction of the through hole (56a) is different from the direction of the screw groove (51) (52). Gas can be blown out in a direction different from the direction of the thread grooves (51) and (52) opened in 21). Therefore, when it is desired to change the direction of the penetration, it can be changed by replacing the external thread member (56) with a different through hole (56a). The holes having the thread grooves (51) and (52) need not necessarily be formed obliquely, and may be perpendicular to the coil surface. Then, as shown in Fig. 10 (b), the screw groove (52) formed in the hole perpendicular to the coil surface and the male screw member (56) having the inclined through hole (56a) are formed. By being combined, a gas outlet in an inclined direction can be obtained.

It is desirable that the tops of the external thread members (54), (55), and (56) do not come out of the coil surface.

The male screw members (54), (55), (56) can be prepared in various specifications, and the direction and thickness of the through holes (55a), (56a), By changing the shape according to the substrate (S) and source gas, the induction heating coil (21) can be used as it is, and only the male screw members (54) (55) (56) need to be changed. This can respond to changes in the specifications of substrate processing.

The male screw member is made of the same material as the high-frequency coil so as not to adversely affect the induction heating coil (21). For example, copper or brass is used in correspondence with the copper induction heating coil (21). Is done.

Although not shown, the through hole provided in the male screw member may be spiral, and the gas blown out from the spiral through hole is turned into a swirling flow, and the raw material gas on the substrate (S) is removed. This can contribute to obtaining a uniform turbulence state.

Coil body ₍₂ 2) of the inner peripheral portion Callout gas are provided in the mouth (29) is intended to show in FIG. 4 (a), but is provided on the opposite surface of the coil (21), the coil body The gas outlet provided in the inner peripheral portion of (22) is more preferably provided in the inner peripheral surface as shown in FIG. The gas outlet (57) shown in Fig. 11 (a) is provided on the inner peripheral surface of the central space of the coil body (22), and is substantially even around the central axis of the coil (21). The gas outlet (57) is arranged at an angle, and the direction of the gas outlet (57) is directed toward the outside of the facing surface and toward the center axis of the coil (21). The directions of these gas outlets (57) are such that they are connected at one point on the central axis of the coil (21) and on the substrate (S). The gas outlet (58) shown in Fig. 11 (b) is provided on the inner peripheral surface of the central space of the coil body (22), and is centered on the central axis of the coil (21). Gas is blown The direction of the outlet (58) is inclined in the horizontal plane with respect to the direction of the central axis of the coil (21).

Since there is no conductor forming the coil in the center of the induction heating coil (21), it is difficult to uniformly supply the source gas to this part. However, the gas outlet (57) (58) By providing (58) as described above, even under the center of the coil (21), the source gas is sufficiently supplied to improve the uniformity during the gas phase reaction treatment. Can be.

The gas outlets provided in the center space of the coil body (22) are the ones shown in Fig. 4 (a) (29) and those shown in Figs. 11 (a) and (b) (57 ) (58) and may be provided, and only one of the chairs may be provided.

The induction heating coil (21) shown in FIGS. 2 and 3 has a power connection terminal connected to the inner peripheral end and the outer peripheral end thereof, and is driven by a high frequency power supply.

For the high-frequency power supply (high-frequency oscillator), for example, an IGBT (gate-insulated bipolar transistor), which is a power semiconductor switching element, is used. Industrial applicability

The induction heating coil according to the present invention includes a heating means of a substrate processing (CVD: Chemical Vapor Deposition) apparatus for producing a crystalline film or other thin films using a gas phase reaction. Suitable for use.

Claims

The scope of the claims

1. An induction heating coil in which a gas inlet and a plurality of gas outlets that communicate with the outside are provided at predetermined positions of a gas flow path formed inside, respectively.

An induction heating coil, characterized in that at least one gas outlet is provided with a thread groove on the inner peripheral surface.

2. The coil for induction heating according to claim 1, wherein the gas outlet is open on the side of the coil that forms the planar induction electric field.

3. The coil according to claim 1, wherein the coil has a flat spiral shape, and a gas outlet is provided on a side surface of the central portion and has a slope at a center of the spiral. Induction heating coil.

4. The induction heating coil according to claim 2, wherein a predetermined screw member is screwed into the screw groove.

5. The induction heating coil according to claim 4, wherein the screw member has a gas blowing through hole penetrating the screw member in the screwing direction.